Matthew Garrett [Mon, 6 Feb 2012 20:14:40 +0000 (15:14 -0500)]
hfsplus: add an ioctl to bless files
Making an hfsplus partition bootable requires the ability to "bless" a
file by putting its inode number in the volume header. Doing this from
userspace on a mounted filesystem is impractical since the kernel will
write back the original values on unmount. Add an ioctl to allow userspace
to update the volume header information based on the target file.
Signed-off-by: Matthew Garrett <mjg@redhat.com> Signed-off-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Matthew Garrett [Thu, 2 Feb 2012 20:39:50 +0000 (15:39 -0500)]
hfsplus: change finder_info to u32
The finder_info block in the hfsplus volume header is currently defined as
an array of 8 bit values, but TN1150 defines it as being an array of 32 bit
values. Fix for convenience.
Signed-off-by: Matthew Garrett <mjg@redhat.com> Signed-off-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Matthew Garrett [Tue, 13 Mar 2012 16:10:34 +0000 (12:10 -0400)]
hfsplus: initialise userflags
The userflags field was being written to the filesystem without being
initialised. Make sure it's clear, since otherwise files end up with
garbage attributes.
Signed-off-by: Matthew Garrett <mjg@redhat.com> Signed-off-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Al Viro [Wed, 14 Mar 2012 02:06:28 +0000 (22:06 -0400)]
aio: fix the comment in aio_kick_handler()
It should've been changed when queue_work() became
queue_delayed_work(..., 0) in there. It's always had been
about not needing a delay, not about not using specific
function...
Kai Bankett [Fri, 17 Feb 2012 04:59:20 +0000 (05:59 +0100)]
fs: initial qnx6fs addition
Adds support for qnx6fs readonly support to the linux kernel.
* Mount option
The option mmi_fs can be used to mount Harman Becker/Audi MMI 3G
HDD qnx6fs filesystems.
* Documentation
A high level filesystem stucture description can be found in the
Documentation/filesystems directory. (qnx6.txt)
* Additional features
- Active (stable) superblock selection
- Superblock checksum check (enforced)
- Supports mount of qnx6 filesystems with to host different endianess
- Automatic endianess detection
- Longfilename support (with non-enfocing crc check)
- All blocksizes (512, 1024, 2048 and 4096 supported)
Signed-off-by: Kai Bankett <chaosman@ontika.net> Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Al Viro [Mon, 13 Feb 2012 02:56:08 +0000 (21:56 -0500)]
procfs: clean proc_fill_super() up
First of all, there's no need to zero ->i_uid/->i_gid on root inode -
both had been set to zero already. Moreover, let's take the iput()
on failure to the failure exit it belongs to...
Al Viro [Mon, 13 Feb 2012 00:43:17 +0000 (19:43 -0500)]
vfs: turn generic_drop_inode() into static inline
Once upon a time it used to be much bigger, but these days there's
no point whatsoever keeping it in fs/inode.c, especially since
it's not even needed as initializer for ->drop_inode() - it's the
default and leaving ->drop_inode NULL will do just as well.
Al Viro [Mon, 6 Feb 2012 17:45:27 +0000 (12:45 -0500)]
vfs: check i_nlink limits in vfs_{mkdir,rename_dir,link}
New field of struct super_block - ->s_max_links. Maximal allowed
value of ->i_nlink or 0; in the latter case all checks still need
to be done in ->link/->mkdir/->rename instances. Note that this
limit applies both to directoris and to non-directories.
Jason Baron [Fri, 16 Mar 2012 20:34:03 +0000 (16:34 -0400)]
Don't limit non-nested epoll paths
Commit 28d82dc1c4ed ("epoll: limit paths") that I did to limit the
number of possible wakeup paths in epoll is causing a few applications
to longer work (dovecot for one).
The original patch is really about limiting the amount of epoll nesting
(since epoll fds can be attached to other fds). Thus, we probably can
allow an unlimited number of paths of depth 1. My current patch limits
it at 1000. And enforce the limits on paths that have a greater depth.
This is captured in: https://bugzilla.redhat.com/show_bug.cgi?id=681578
Signed-off-by: Jason Baron <jbaron@redhat.com> Cc: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Pull networking changes from David Miller:
"1) icmp6_dst_alloc() returns NULL instead of ERR_PTR() leading to
crashes, particularly during shutdown. Reported by Dave Jones and
fixed by Eric Dumazet.
2) hyperv and wimax/i2400m return NETDEV_TX_BUSY when they have
already freed the SKB, which causes crashes as to the caller this
means requeue the packet. Fixes from Eric Dumazet.
3) usbnet driver doesn't allocate the right amount of headroom on
fresh RX SKBs, fix from Eric Dumazet.
4) Fix regression in ip6_mc_find_dev_rcu(), as an RCU lookup it
abolutely should not take a reference to 'dev', this leads to
leaks. Fix from RonQing Li.
5) Fix netfilter ctnetlink race between delete and timeout expiration.
From Pablo Neira Ayuso.
6) Revert SFQ change which causes regressions, specifically queueing
to tail can lead to unavoidable flow starvation. From Eric
Dumazet.
7) Fix a memory leak and a crash on corrupt firmware files in bnx2x,
from Michal Schmidt."
* git://git.kernel.org/pub/scm/linux/kernel/git/davem/net:
netfilter: ctnetlink: fix race between delete and timeout expiration
ipv6: Don't dev_hold(dev) in ip6_mc_find_dev_rcu.
wimax/i2400m: fix erroneous NETDEV_TX_BUSY use
net/hyperv: fix erroneous NETDEV_TX_BUSY use
net/usbnet: reserve headroom on rx skbs
bnx2x: fix memory leak in bnx2x_init_firmware()
bnx2x: fix a crash on corrupt firmware file
sch_sfq: revert dont put new flow at the end of flows
ipv6: fix icmp6_dst_alloc()
Linus Torvalds [Sat, 17 Mar 2012 16:54:16 +0000 (09:54 -0700)]
Merge branch 'perf-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull perf fixes from Ingo Molnar.
* 'perf-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
perf tools, x86: Build perf on older user-space as well
perf tools: Use scnprintf where applicable
perf tools: Incorrect use of snprintf results in SEGV
netfilter: ctnetlink: fix race between delete and timeout expiration
Kerin Millar reported hardlockups while running `conntrackd -c'
in a busy firewall. That system (with several processors) was
acting as backup in a primary-backup setup.
After several tries, I found a race condition between the deletion
operation of ctnetlink and timeout expiration. This patch fixes
this problem.
Tested-by: Kerin Millar <kerframil@gmail.com> Reported-by: Kerin Millar <kerframil@gmail.com> Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org> Signed-off-by: David S. Miller <davem@davemloft.net>
RongQing.Li [Thu, 15 Mar 2012 22:54:14 +0000 (22:54 +0000)]
ipv6: Don't dev_hold(dev) in ip6_mc_find_dev_rcu.
ip6_mc_find_dev_rcu() is called with rcu_read_lock(), so don't
need to dev_hold().
With dev_hold(), not corresponding dev_put(), will lead to leak.
[ bug introduced in 96b52e61be1 (ipv6: mcast: RCU conversions) ]
Signed-off-by: RongQing.Li <roy.qing.li@gmail.com> Acked-by: Eric Dumazet <eric.dumazet@gmail.com> Signed-off-by: David S. Miller <davem@davemloft.net>
Linus Torvalds [Sat, 17 Mar 2012 00:14:55 +0000 (17:14 -0700)]
Merge branch 'akpm' (more patches from Andrew)
Merge some more email patches from Andrew Morton:
"A couple of nilfs fixes"
* emailed from Andrew Morton <akpm@linux-foundation.org>:
nilfs2: fix NULL pointer dereference in nilfs_load_super_block()
nilfs2: clamp ns_r_segments_percentage to [1, 99]
Ryusuke Konishi [Sat, 17 Mar 2012 00:08:39 +0000 (17:08 -0700)]
nilfs2: fix NULL pointer dereference in nilfs_load_super_block()
According to the report from Slicky Devil, nilfs caused kernel oops at
nilfs_load_super_block function during mount after he shrank the
partition without resizing the filesystem:
Haogang Chen [Sat, 17 Mar 2012 00:08:38 +0000 (17:08 -0700)]
nilfs2: clamp ns_r_segments_percentage to [1, 99]
ns_r_segments_percentage is read from the disk. Bogus or malicious
value could cause integer overflow and malfunction due to meaningless
disk usage calculation. This patch reports error when mounting such
bogus volumes.
Linus Torvalds [Sat, 17 Mar 2012 00:04:02 +0000 (17:04 -0700)]
Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/jmorris/linux-security
Pull maintainer update from James Morris:
"Please pull this patch which adds Serge as maintainer of the
capabilities code, as discussed on lwn and the lsm list.
New capabilities must be signed off by the maintainer, and new uses of
any capabilities should at be cc'd to the maintainer."
* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/jmorris/linux-security:
MAINTAINERS: Add Serge as maintainer of capabilities
Linus Torvalds [Sat, 17 Mar 2012 00:03:15 +0000 (17:03 -0700)]
Merge tag 'for-linus' of git://linux-c6x.org/git/projects/linux-c6x-upstreaming
Pull c6x bugfix from Mark Salter:
"Remove dead code from entry.S which causes a build failure when using
a newer assembler (v2.22 complains about it, v2.20 ignores it)."
* tag 'for-linus' of git://linux-c6x.org/git/projects/linux-c6x-upstreaming:
C6X: remove dead code from entry.S
Mark Salter [Fri, 16 Mar 2012 13:27:57 +0000 (09:27 -0400)]
C6X: remove dead code from entry.S
The ENDPROC() on sys_fadvise64_c6x() in arch/c6x/kernel/entry.S is
outside of the conditional block with the matching ENTRY() macro. This
leads a newer (v2.22 vs. v2.20) assembler to complain:
/tmp/ccGZBaPT.s: Assembler messages:
/tmp/ccGZBaPT.s: Error: .size expression for sys_fadvise64_c6x does not evaluate to a constant
The conditional block became dead code when c6x switched to generic
unistd.h and should be removed along with the offending ENDPROC().
Signed-off-by: Mark Salter <msalter@redhat.com> Acked-by: David Howells <dhowells@redhat.com>
Eric Dumazet [Wed, 14 Mar 2012 09:21:44 +0000 (09:21 +0000)]
wimax/i2400m: fix erroneous NETDEV_TX_BUSY use
A driver start_xmit() method cannot free skb and return NETDEV_TX_BUSY,
since caller is going to reuse freed skb.
In fact netif_tx_stop_queue() / netif_stop_queue() is needed before
returning NETDEV_TX_BUSY or you can trigger a ksoftirqd fatal loop.
In case of memory allocation error, only safe way is to drop the packet
and return NETDEV_TX_OK
Also increments tx_dropped counter
Signed-off-by: Eric Dumazet <eric.dumazet@gmail.com> Cc: Inaky Perez-Gonzalez <inaky.perez-gonzalez@intel.com> Signed-off-by: David S. Miller <davem@davemloft.net>
Eric Dumazet [Wed, 14 Mar 2012 06:56:25 +0000 (06:56 +0000)]
net/usbnet: reserve headroom on rx skbs
network drivers should reserve some headroom on incoming skbs so that we
dont need expensive reallocations, eg forwarding packets in tunnels.
This NET_SKB_PAD padding is done in various helpers, like
__netdev_alloc_skb_ip_align() in this patch, combining NET_SKB_PAD and
NET_IP_ALIGN magic.
Signed-off-by: Eric Dumazet <eric.dumazet@gmail.com> Cc: Oliver Neukum <oneukum@suse.de> Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Acked-by: Oliver Neukum <oneukum@suse.de> Signed-off-by: David S. Miller <davem@davemloft.net>
Michal Schmidt [Thu, 15 Mar 2012 14:08:29 +0000 (14:08 +0000)]
bnx2x: fix memory leak in bnx2x_init_firmware()
When cycling the interface down and up, bnx2x_init_firmware() knows that
the firmware is already loaded, but nevertheless it allocates certain
arrays anew (init_data, init_ops, init_ops_offsets, iro_arr). The old
arrays are leaked.
Fix the leaks by returning early if the firmware was already loaded.
Because if the firmware is loaded, so are the arrays.
Signed-off-by: Michal Schmidt <mschmidt@redhat.com> Acked-by: Eilon Greenstein <eilong@broadcom.com> Signed-off-by: David S. Miller <davem@davemloft.net>
Michal Schmidt [Thu, 15 Mar 2012 14:08:28 +0000 (14:08 +0000)]
bnx2x: fix a crash on corrupt firmware file
If the requested firmware is deemed corrupt and then released, reset the
pointer to NULL in order to avoid double-freeing it in
bnx2x_release_firmware() or dereferencing it in bnx2x_init_firmware().
Signed-off-by: Michal Schmidt <mschmidt@redhat.com> Acked-by: Eilon Greenstein <eilong@broadcom.com> Signed-off-by: David S. Miller <davem@davemloft.net>
Eric Dumazet [Tue, 13 Mar 2012 18:04:25 +0000 (18:04 +0000)]
sch_sfq: revert dont put new flow at the end of flows
This reverts commit d47a0ac7b6 (sch_sfq: dont put new flow at the end of
flows)
As Jesper found out, patch sounded great but has bad side effects.
In stress situation, pushing new flows in front of the queue can prevent
old flows doing any progress. Packets can stay in SFQ queue for
unlimited amount of time.
It's possible to add heuristics to limit this problem, but this would
add complexity outside of SFQ scope.
A more sensible answer to Dave Taht concerns (who reported the issued I
tried to solve in original commit) is probably to use a qdisc hierarchy
so that high prio packets dont enter a potentially crowded SFQ qdisc.
Reported-by: Jesper Dangaard Brouer <jdb@comx.dk> Cc: Dave Taht <dave.taht@gmail.com> Signed-off-by: Eric Dumazet <eric.dumazet@gmail.com> Signed-off-by: David S. Miller <davem@davemloft.net>
Linus Torvalds [Fri, 16 Mar 2012 00:16:22 +0000 (17:16 -0700)]
Merge branch 'akpm' (Andrew's patch-bomb)
Merge patches from Andrew Morton:
"Nine patches - some bug fixes and some MAINTAINERS fiddling."
* emailed from Andrew Morton <akpm@linux-foundation.org>:
drivers/video/backlight/s6e63m0.c: fix corruption storing gamma mode
MAINTAINERS: add entry for exynos mipi display drivers
MAINTAINERS: fix link to Gustavo Padovans tree
MAINTAINERS: add Johan to Bluetooth maintainers
MAINTAINERS: Gustavo has moved
prctl: use CAP_SYS_RESOURCE for PR_SET_MM option
rapidio/tsi721: fix bug in register offset definitions
MAINTAINERS: update ST's Mailing list for SPEAr
memcg: free mem_cgroup by RCU to fix oops
Linus Torvalds [Fri, 16 Mar 2012 00:14:35 +0000 (17:14 -0700)]
Merge branch 'i2c-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/jdelvare/staging
Pull i2c subsystem fixes from Jean Delvare.
* 'i2c-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/jdelvare/staging:
i2c-algo-bit: Fix spurious SCL timeouts under heavy load
i2c-core: Comment says "transmitted" but means "received"
Linus Torvalds [Fri, 16 Mar 2012 00:13:39 +0000 (17:13 -0700)]
Merge tag 'hwmon-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/groeck/linux-staging
Pull hwmon fixes from Guenter Roeck.
* tag 'hwmon-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/groeck/linux-staging:
hwmon: (zl6100) Enable interval between chip accesses for all chips
hwmon: (w83627ehf) Describe undocumented pwm attributes
hwmon: (w83627ehf) Fix temp2 source for W83627UHG
hwmon: (w83627ehf) Fix memory leak in probe function
hwmon: (w83627ehf) Fix writing into fan_stop_time for NCT6775F/NCT6776F
Linus Torvalds [Fri, 16 Mar 2012 00:07:25 +0000 (17:07 -0700)]
Merge branch 'drm-fixes' of git://people.freedesktop.org/~airlied/linux
Pull drm exynos/intel updates from Dave Airlie:
"Two minor updates from Jesse for Intel SNB fixes, and a few fixes from
Samsung for exynos. The pull req has Alan's commit in it since Intel
based their tree on my tree at that time, but it all seems fine wrt
merging."
* 'drm-fixes' of git://people.freedesktop.org/~airlied/linux:
drm exynos: use drm_fb_helper_set_par directly
drm/exynos: Fix fb_videomode <-> drm_mode_modeinfo conversion
drm/exynos: fix runtime_pm fimd device state on probe
drm/exynos: use correct 'exynos-drm' name for platform device
drm/i915: support 32 bit BGR formats in sprite planes
drm/i915: fix color order for BGR formats on SNB
drm/gma500: Fix Cedarview boot failures in 3.3-rc
Linus Torvalds [Fri, 16 Mar 2012 00:06:05 +0000 (17:06 -0700)]
Merge branch 'v4l_for_linus' of git://git.kernel.org/pub/scm/linux/kernel/git/mchehab/linux-media
Pull media fixes from Mauro Carvalho Chehab:
"For 4 fixes for 3.3 (all trivial):
- uvc video driver: fixes a division by zero;
- davinci: add module.h to fix compilation;
- smsusb: fix the delivery system setting;
- smsdvb: the get_frontend implementation there is broken.
The smsdvb patch has 127 lines, but it is trivial: instead of
returning a cache of the set_frontend (with is wrong, as it doesn't
have the updated values for the data, and the implementation there is
buggy), it copies the information of the detected DVB parameters from
the smsdvb private structures into the corresponding DVBv5 struct
fields."
* 'v4l_for_linus' of git://git.kernel.org/pub/scm/linux/kernel/git/mchehab/linux-media:
[media] smsdvb: fix get_frontend
[media] smsusb: fix the default delivery system setting
[media] media: davinci: added module.h to resolve unresolved macros
[media] [FOR,v3.3] uvcvideo: Avoid division by 0 in timestamp calculation
Linus Torvalds [Fri, 16 Mar 2012 00:04:56 +0000 (17:04 -0700)]
Merge branch '3.3-urgent' of git://git.kernel.org/pub/scm/linux/kernel/git/nab/target-pending
Pull target fixes from Nicholas Bellinger:
"This series addresses two recently reported regression bugs related to
legacy SCSI reservation usage in target core, and iscsi-target
reservation conflict handling.
The second patch in particular addresses possible data-corruption with
SCSI reservations that is specific to iscsi-target fabric LUNs with
multiple client writers. Both patches need to go into v3.2 stable
ASAP, and the branch based on the last target-pending/3.3-rc-fixes
HEAD.
Again, thanks to Martin Svec for his help to identify and address this
regression bug with iscsi-target."
strict_strtoul() writes a long but ->gamma_mode only has space to store an
int, so on 64 bit systems we end up scribbling over ->gamma_table_count as
well. I've changed it to use kstrtouint() instead.
Donghwa Lee [Thu, 15 Mar 2012 22:17:11 +0000 (15:17 -0700)]
MAINTAINERS: add entry for exynos mipi display drivers
I'd like to add Inki Dae, Donghwa Lee and Kyungmin Park as maintainers
who developers for exynos mipi display drivers for
video/driver/exynos/exynos_mipi* and include/video/exynos_mipi*.
Signed-off-by: Donghwa Lee <dh09.lee@samsung.com> Signed-off-by: Inki Dae <inki.dae@samsung.com> Signed-off-by: Kyungmin Park <kyungmin.park@samsung.com> Cc: Florian Tobias Schandinat <FlorianSchandinat@gmx.de> Cc: Richard Purdie <rpurdie@rpsys.net> Cc: Kukjin Kim <kgene.kim@samsung.com> Cc: Jingoo Han <jg1.han@samsung.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Johan Hedberg [Thu, 15 Mar 2012 22:17:11 +0000 (15:17 -0700)]
MAINTAINERS: add Johan to Bluetooth maintainers
I've been coordinating Bluetooth patches in my tree for some time and
it's possible I'll do it in the future too, so add myself to the
Bluetooth sections as well as mention my tree there.
Signed-off-by: Johan Hedberg <johan.hedberg@intel.com> Cc: Marcel Holtmann <marcel@holtmann.org> Cc: "Gustavo F. Padovan" <padovan@profusion.mobi> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Cyrill Gorcunov [Thu, 15 Mar 2012 22:17:10 +0000 (15:17 -0700)]
prctl: use CAP_SYS_RESOURCE for PR_SET_MM option
CAP_SYS_ADMIN is already overloaded left and right, so to have more
fine-grained access control use CAP_SYS_RESOURCE here.
The CAP_SYS_RESOUCE is chosen because this prctl option allows a current
process to adjust some fields of memory map descriptor which rather
represents what the process owns: pointers to code, data, stack
segments, command line, auxiliary vector data and etc.
Suggested-by: Michael Kerrisk <mtk.manpages@gmail.com> Acked-by: Kees Cook <keescook@chromium.org> Acked-by: Michael Kerrisk <mtk.manpages@gmail.com> Cc: Pavel Emelyanov <xemul@parallels.com> Cc: Tejun Heo <tj@kernel.org> Cc: Oleg Nesterov <oleg@redhat.com> Cc: Paul Bolle <pebolle@tiscali.nl> Cc: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com> Signed-off-by: Cyrill Gorcunov <gorcunov@openvz.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
rapidio/tsi721: fix bug in register offset definitions
Fix indexed register offset definitions that use decimal (wrong) instead
of hexadecimal (correct) notation for indexing multipliers.
Incorrect definitions do not affect Tsi721 driver in its current default
configuration because it uses only IDB queue 0. Loss of inbound
doorbell functionality should be observed if queue other than 0 is used.
Signed-off-by: Alexandre Bounine <alexandre.bounine@idt.com> Cc: Matt Porter <mporter@kernel.crashing.org> Cc: Chul Kim <chul.kim@idt.com> Cc: <stable@vger.kernel.org> [3.2+] Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Viresh Kumar [Thu, 15 Mar 2012 22:17:09 +0000 (15:17 -0700)]
MAINTAINERS: update ST's Mailing list for SPEAr
We have created a ST's Mailing list for SPEAr. This can be accessed
from non-st email ids. I want people to cc this list, when they have
changes specific to SPEAr. So, its better to get this updated in
MAINTAINERS file.
linux-arm-kernel@lists.infradead.org is also added for SPEAr.
Signed-off-by: Viresh Kumar <viresh.kumar@st.com> Cc: Russell King <rmk@arm.linux.org.uk> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Hugh Dickins [Thu, 15 Mar 2012 22:17:07 +0000 (15:17 -0700)]
memcg: free mem_cgroup by RCU to fix oops
After fixing the GPF in mem_cgroup_lru_del_list(), three times one
machine running a similar load (moving and removing memcgs while
swapping) has oopsed in mem_cgroup_zone_nr_lru_pages(), when retrieving
memcg zone numbers for get_scan_count() for shrink_mem_cgroup_zone():
this is where a struct mem_cgroup is first accessed after being chosen
by mem_cgroup_iter().
Just what protects a struct mem_cgroup from being freed, in between
mem_cgroup_iter()'s css_get_next() and its css_tryget()? css_tryget()
fails once css->refcnt is zero with CSS_REMOVED set in flags, yes: but
what if that memory is freed and reused for something else, which sets
"refcnt" non-zero? Hmm, and scope for an indefinite freeze if refcnt is
left at zero but flags are cleared.
It's tempting to move the css_tryget() into css_get_next(), to make it
really "get" the css, but I don't think that actually solves anything:
the same difficulty in moving from css_id found to stable css remains.
But we already have rcu_read_lock() around the two, so it's easily fixed
if __mem_cgroup_free() just uses kfree_rcu() to free mem_cgroup.
However, a big struct mem_cgroup is allocated with vzalloc() instead of
kzalloc(), and we're not allowed to vfree() at interrupt time: there
doesn't appear to be a general vfree_rcu() to help with this, so roll
our own using schedule_work(). The compiler decently removes
vfree_work() and vfree_rcu() when the config doesn't need them.
Signed-off-by: Hugh Dickins <hughd@google.com> Acked-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com> Acked-by: Johannes Weiner <hannes@cmpxchg.org> Cc: Konstantin Khlebnikov <khlebnikov@openvz.org> Cc: Tejun Heo <tj@kernel.org> Cc: Ying Han <yinghan@google.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Ville Syrjala [Thu, 15 Mar 2012 17:11:05 +0000 (18:11 +0100)]
i2c-algo-bit: Fix spurious SCL timeouts under heavy load
When the system is under heavy load, there can be a significant delay
between the getscl() and time_after() calls inside sclhi(). That delay
may cause the time_after() check to trigger after SCL has gone high,
causing sclhi() to return -ETIMEDOUT.
To fix the problem, double check that SCL is still low after the
timeout has been reached, before deciding to return -ETIMEDOUT.
Signed-off-by: Ville Syrjala <syrjala@sci.fi> Cc: stable@vger.kernel.org Signed-off-by: Jean Delvare <khali@linux-fr.org>